1. Field of the Invention
The present invention generally relates to accoustic wave devices such as transducers and more particularly to the electric connection of such transducers to other circuit members.
2. Description of the Prior Art
Transducers, which are generally well known in the art, are made of piezoelectric material. When the piezoelectric material is excited such as by an electrical signal, the transducer will vibrate and, in some applications, will produce a noise in response thereto.
In one kind of application, a transducer in the form of a thin piezoelectric element is mounted on a conductive substrate. By connecting an electrical signal to the element and the other to the conductive substrate, the transducer will be driven (or vibrated) at a given frequency.
In order to get a larger sound output from a transducer of this type, the piezoelectric element is divided into two electrically isolated portions. A feedback circuit is then connected to one of the piezoelectric portions as is disclosed in U.S. Pat. No. 3,815,129. This type of assembly using three terminal connections, one to the conductive substrate and one each to the two portions of the piezoelectric element, will produce a much greater sound out put than the conventional manner of attaching a terminal merely to the conductive substrate and one to the piezoelectric element. A representative type of circuit to produce the desired sound is also disclosed in said U.S. Pat. No. 3,815,129, the contents of which are incorporated by reference herein.
In the past, the units which mount an electrically connected transducer of the type described, have a permanent, non-cyclable means of attaching or mounting the transducer to the unit, either by means of a solder connection or some sort of cement. Examples of units of this type as disclosed in U.S. Pat. Nos. 4,013,982 and 3,331,970.
It is found to be desirable for both assembly and manufacturing purposes, to mount a transducer of the type described herein in a non-permanent manner. One example of an assembly which accomplishes this general purpose is disclosed in U.S. Pat. No. 3,885,173. This patent discloses an apparatus which includes a gasket and a housing wherein the gasket is made of resilient material having conducting regions. The gasket is then layed upon a printed circuit board and the transducer is mounted thereover. A housing provides the necessary mechanical coupling for pressing the transducer against the gasket to electrically connect the transducer to the printed circuit board.
Although the apparatus disclosed in U.S. Pat. No. 3,885,173 accomplishes its intended purposes, it is expensive in that it uses an elastomeric gasket and it does not lend itself to easy assembly in an ordinary manufacturing production process.